Final answer:
To identify a mineral, hardness is typically assessed first using the Mohs' scale, followed by observing properties such as color, streak, luster, and cleavage. Option A is correct.
Step-by-step explanation:
When identifying a mineral, the first property to use is typically its hardness, which is its ability to resist abrasion or scratching. This property is measured using the Mohs' scale of mineral hardness. Besides hardness, one could observe the mineral's color, although it can be misleading due to impurities causing color variations in the same mineral type.
The streak of a mineral, which is the color of its powdered form after being rubbed on a streak plate, can also be useful, particularly for metallic minerals. Additionally, the way a mineral reflects light, known as its luster, alongside its cleavage, which refers to the way a mineral breaks along certain planes, can be diagnostic.
Determining mineral hardness in the field or the classroom can involve using common objects as references on the Mohs scale. Another important identification method is looking at the mineral's cleavage by shining a light on its surface to check for brilliant light reflections indicating cleavage planes.
Other characteristics such as density, texture, and mineral content are also considered when differentiating minerals, especially when examining hand specimens or viewing under a microscope if phenocrysts are present.